An alkaline urine pH can be the result of which condition?

• A. Urinary tract obstruction
• B. Uncontrolled diabetes
• C. Prolonged diarrhea
• D. Starvation

Answer: (A)

Alkaline urine pH usually points to urine that has been exposed to ammonia produced by urease-producing bacteria, which raise the pH by converting urea into ammonia. In practice, this most often occurs when urine is left stagnant or infected, such as with urinary tract obstruction that allows bacterial growth and infection. The obstruction creates urinary stasis, which makes it easier for urease-positive organisms (like Proteus or Klebsiella) to colonize and alkalinize the urine.

Diabetes, prolonged diarrhea, and starvation tend to produce acidic urine. Diabetes, especially with ketoacidosis, leads to acidic urine from ketones. Prolonged diarrhea causes bicarbonate loss and metabolic acidosis, and starvation can lead to ketosis as well, both of which lower the urine pH rather than raise it.

So, urinary tract obstruction fits as the condition that can result in alkaline urine by promoting infection with urease-producing bacteria.